Evaluación técnica de un aspersor de impacto
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Date
2012
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Publisher
Universidad de Concepción
Abstract
Este estudio tuvo como objetivo evaluar un aspersor de impacto, midiendo el efecto de la presión de operación, velocidad del viento y espaciamientos entre aspersores sobre la uniformidad del riego. El aspersor seleccionado está diseñado para trabajar, según catalogo, a presiones de 150 a 500 kPa, consta de cinco boquillas intercambiables de 12, 14, 16, 18 y 20 mm , una boquilla fija de 8 mm y un caudal que varia de 9,5 a 39,40 m3 h1. La evaluación del aspersor se realizó en condiciones de campo, con presiones de trabajo de 200, 300 y 400 kPa, en los cinco tipos de boquillas disponibles. Se utilizaron dos rangos de velocidad de viento: menor a 1 m s1 y mayor a 1 m s 1, y espaciamientos entre aspersores y laterales de 28x28 a 42x42 m. En un área de trabajo de 6400 m² se utilizó un arreglo de 4 x 4 metros en la cual se ubicaron vasos de captación que permitieron obtener la precipitación del aspersor. La uniformidad del riego se estimó mediante el coeficiente de uniformidad de Christiansen (CU). Los resultados muestran que los mayores CU se encontraron para una presión de 400 kPa. El CU varió entre 18,3 a 92 %, mientras que para 2 una presión de 300 kPa se observaron valores entre 57,6 a 91.6 % para una presión de 200 kPa se observaron valores entre 45 a 84 %. El viento afectó el coeficiente de uniformidad. Para una presión de 300 kPa con velocidades de viento menores 1 m*s 1 el C.U. obtenido fue de 91,6 a 75,1 %, para velocidades de viento mayores a 1 m*s 1 el coeficiente de uniformidad se estimó entre 57,5 a 82,2 %. El efecto en el coeficiente de uniformidad de los espaciamientos dependen de las presiones y el diámetro de las boquillas. Los valores de C.U. estuvieron en el rango de 92% con una presión de 400 kPa y diámetro de boquilla de 16 mm, y 49,6% con una presión de 200 kPa y diámetro de boquilla de 18 mm. Se compararon los caudales y alcance del catálogo respecto a los obtenidos durante la evaluación. Los caudales medidos fueron un 7.5 % mas altos que los registrados por catalogo, y los radios del aspersor también fueron un 7 % mayor a los encontrados en el catálogo.
The objective of this study was to evaluate an impact sprinkler measuring the effect of pressure, wind speed and spacing between sprinklers on irrigation uniformity. The sprinkler selected is designed to work at pressures from 150 to 500 kPa, it has five interchangeable nozzles of 12,14,16,18 and 20 mm, a fixed nozzle of 8 mm and a flow rate ranging from 9,5 to 39,4 m3h1. The evaluation was conducted under field conditions, with working pressures of 200, 300 and 400 kPa, and the five sizes of nozzles available. Two wind speed ranges were used: less and greater than 1 m s 1, and spacing between sprinklers from 28x28 to 42x42 m. An array of 4x4 meters in a working area of 6400 m2 was used to measure the precipitation under the sprinkler. The uniformity of irrigation was estimated by the Christiansen uniformity coefficient (CU). Results show that higher uniformities were found for a pressure of 400 kPa with CU ranged between 18,3 to 92 %. For a pressure of 300 kPa the values of uniformity were between 57,6 to 91,6 % and for 200 kPa the values were between 47 to 84 %. The wind speed affected the uniformity coefficient. For a pressure of 300 k Pawith wind speed under 1 m s 1 the CU values ranged from 91,6 % to 75,1 %, for wind speed above 1 m s 1 the CU was estimated between 57,5 and 82,2 %. The effect of sprinkler spacing on CU relies on the working pressure and nozzle diameter. CU was around 92% with a pressure of 400 kPa and a nozzle diameter of 16 mm, while that a CU of 49,6 % was estimated for a pressure of 200 kPa and nozzle diameter of 18 mm. It was compared the coverage radius and flow of the sprinkler from the information found in catalog with those obtained during this evaluation. The measured flow rates and sprinkler coverage radios were 7,5 % and 7 % higher respectively than those recorded by catalog.
The objective of this study was to evaluate an impact sprinkler measuring the effect of pressure, wind speed and spacing between sprinklers on irrigation uniformity. The sprinkler selected is designed to work at pressures from 150 to 500 kPa, it has five interchangeable nozzles of 12,14,16,18 and 20 mm, a fixed nozzle of 8 mm and a flow rate ranging from 9,5 to 39,4 m3h1. The evaluation was conducted under field conditions, with working pressures of 200, 300 and 400 kPa, and the five sizes of nozzles available. Two wind speed ranges were used: less and greater than 1 m s 1, and spacing between sprinklers from 28x28 to 42x42 m. An array of 4x4 meters in a working area of 6400 m2 was used to measure the precipitation under the sprinkler. The uniformity of irrigation was estimated by the Christiansen uniformity coefficient (CU). Results show that higher uniformities were found for a pressure of 400 kPa with CU ranged between 18,3 to 92 %. For a pressure of 300 kPa the values of uniformity were between 57,6 to 91,6 % and for 200 kPa the values were between 47 to 84 %. The wind speed affected the uniformity coefficient. For a pressure of 300 k Pawith wind speed under 1 m s 1 the CU values ranged from 91,6 % to 75,1 %, for wind speed above 1 m s 1 the CU was estimated between 57,5 and 82,2 %. The effect of sprinkler spacing on CU relies on the working pressure and nozzle diameter. CU was around 92% with a pressure of 400 kPa and a nozzle diameter of 16 mm, while that a CU of 49,6 % was estimated for a pressure of 200 kPa and nozzle diameter of 18 mm. It was compared the coverage radius and flow of the sprinkler from the information found in catalog with those obtained during this evaluation. The measured flow rates and sprinkler coverage radios were 7,5 % and 7 % higher respectively than those recorded by catalog.
Description
Tesis presentada para optar al título de Ingeniero Civil Agrícola
Keywords
Agricultura de precisión, Aspersores, Riego - Chile